Excel tools to demonstrate

Try it! Find the requested percentiles in the above spreadsheet, and place your formulas in column G. For example, P10 indicates the 10^th percentile. Do you see the relationship between the quartiles and certain percentiles? (Again, answers to the right.)

Note that the QUARTILE and PERCENTILE functions are typically used on data sets with a large number of observations. If they are used on a very small data set, you might be surprised at the results. In fact, you might even disagree with them. For example, if the data set has the 5 values 10, 20, 30, 40, and 50, Excel’s PERCENTILE function indicates that the 10^th percentile is 14. This is certainly not a very intuitive answer, and you might disagree with it, but we might ask why someone would want the 10^th percentile of a 5-value data set in the first place!